1. Field of the Invention
This invention relates generally to pipe fitting covers, a process for covering pipe fittings and to fiberglass insulation for use in insulating pipe elbows. More specifically, the invention relates to pipe fitting covers designed specifically to cover fitting members joined by clamps, flanges, or other devices that protrude from the contour of the piping assembly. Further, the invention relates to a continuous strand of fiberglass comprising a plurality of removably connected individual fiberglass wraps which are uniquely designed to wrap around a pipe elbow to maximize the insulation value in the vicinity of the pipe elbow.
2. Description of the Prior Art
In virtually every instance wherein a cold or hot fluid is being conveyed through piping, insulation of the piping is desirable. It has long been the custom to wrap or place the insulation over the exterior of the piping and to cover the insulation. Insulated piping is covered to further improve the insulation and to enhance appearance.
Early efforts at insulating piping were directed to spreading layers of cement in place by hand on the piping and the pipe fittings and then adhering a fabric thereover followed by additonal coating layers. This procedure was expensive and time consuming. Another method is shown in U.S. Pat. No. 3,620,258 (Graham) which describes the use of a wedge shaped annular element made of resin bonded glass or other mineral fiber in which the fibers are perpendicular to the axes of the elements so that the fibers are axially compressible. While the Graham invention is an improvement over the spreading of cement-fabric layers, nonetheless, the Graham invention is uneconomical and has a significantly reduced insulation value because the axially oriented fibers permit unacceptable heat loss.
It is also known in the art to use a diamond-shaped wrap to insulate a pipe elbow. Such wraps have a pair of opposed points which join in vicinity of the inner radius of the pipe elbow. One such diamond-shaped wrap is produced by Zeston.RTM., Inc. Such diamond-shaped wraps suffer from two primary disadvantages. First, the additional insulation located in the area of the two opposed points of the diamond are a waste of material because they do not add to the insulation value of the wrap. Second, the opposed points of the diamond-shaped wrap tend to bunch up when wrapped around the elbow especially in the vicinity of the inner radius of the elbow. This requires that the insulation be compressed which reduces the R-value. This bunching affect may also require a thicker more expensive type of fitting cover to be employed and more expensive fastening means to fasten the ends of the fitting cover in place.
Thereafter, aluminum and plastic covers for both the piping and the various fittings such as elbows, tees, valves and couplings were provided both with insulating material secured therein and without any insulation. In the instances wherein the insulating materials are adhered to the fitting covers, the insulation and fitting are joined in place at the same time. In those instances where the cover is separate from the insulation, the insulation is usually first formed about the piping and the pipe fittings and thereafter the aluminum or plastic covers are secured over the insulation.
The problem of covering flanged fittings or piping at any point at which a protrusion extends from the streamline surface of a piping assembly has been dealt with for many years. Further, in recent years, mechanical grooved type externally coupled fittings, such as manufactured by VICTAULIC.RTM. Co. and others have been used more frequently in piping assemblies that require insulation. An illustration of an effort to achieve a fitting cover capable of covering and accommodating insulation over the flanged or protruding portions of piping, is seen in U.S. Pat. No. 3,732,894 (Botsolas, May 15, 1973). Therein, the elbow fitting cover is sized to have a uniform inner and outer radius defined by the flange or protrusion on the piping. Further, step collars on the ends of the fitting covers are provided with this cover to facilitate joining the elbow cover or other fitting cover to the pipe extending from the fitting. Similar fitting covers with multiple stepped reducers such as seen in U.S. Pat. No. 3,153,546 (Dunn, October 1964) are also known.
Another effort at covering fittings joined by protruding flanges is illustrated by the fitting covers as seen in U.S. Pat. No. 3,732,894 (Botsolas; May 15, 1973). Both molded fiberglass fittings and urethane foam fittings are used under the PVC cover. Again, the molded fittings and covers have a uniform outer radius and a uniform inner diameter which are a function of the size of the protrusion or flange outside diameter.
Still another effort at dealing with the problem of covering flanges with insulation is shown in U.S. Pat. No. 3,631,898 (Harley, Jan. 4, 1972). The approach taken in the Harley Patent is one wherein half sections of rigid covering material are machined by grinding the rigid insulation internally to the contour of the fitting to be covered. Again, the outer radius of the fitting is essentially constant and uniform and requires a cover member, usually of tough vinyl, again configured to the contour of the insulation. These prior art covers fail to provide an efficient covering for flanged fittings wherein ease of joining adjacent fittings can be attained, nor do these prior art covers provide a single cover that can cover a variety of pipe insulation thicknesses.